JPH047344A - Elastomer composition and its production - Google Patents

Abstract

PURPOSE:To obtain a gel-containing elastomer composition having excellent mechanical properties by mixing a chlorosulfonated polyethylene or a chlorinated polyethylene with an ethylene/alpha-olefin copolymer rubber, a hydrochloric acid binder, an organic peroxide and PP. CONSTITUTION:An elastomer composition prepared by mixing 100 pts.wt. rubber component (A) comprising 60-97wt.% chlorosulfonated polyethylene or chlorinated polyethylene (a) and 3-40wt.% ethylene/alpha-olefin copolymer rubber (b) with 0.1-30 pts.wt. hydrochloric acid binder (B), 0.1-10 pts.wt. organic peroxide (C) and 5-50 pts.wt. polypropylene (D). This composition is obtained by kneading polymer (a) with agent (B) and compound (C), kneading the formed mixture with rubber (b), melt-kneading the resulting mixture with polymer (D) and dynamically heat-treating the final mixture. The obtained composition is a gel- containing elastomer composition improved in mechanical properties without detriment to the excellent physical properties of polymer (a).

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an elastomer composition and a method for producing the same.

The elastomer composition of the present invention and its manufacturing method are used in the rubber processing field or resin processing field.

(Prior technology) Molding and processing of elastomer compositions using rubber as a raw material requires a vulcanization process to crosslink the rubber, but in this method, rubber and polyolefin are kneaded and the rubber is partially crosslinked by dynamic heat treatment. An elastomer composition containing a gel has the characteristics that it can be molded in a short time without requiring a vulcanization process, and that molding costs can be reduced.

For this reason, demand has increased in recent years for elastomer compositions containing gels whose main raw materials are rubber and polyolefin.

Along with this, chlorosulfonated polyethylene or chlorinated polyethylene containing chlorine has better physical properties such as oil resistance, ozone resistance, weather resistance, and bright color than other rubbers, so chlorosulfonated polyethylene Elastic body compositions containing gels whose main raw materials are polyethylene or chlorinated polyethylene and polypropylene, which is a polyolefin, are also on the verge of being put to practical use. However, this elastic body composition is inferior in mechanical properties such as compression set and tensile strength. For example, a rubber mat with poor compression set starts to deform from the beginning of practical use, and deforms significantly during practical use, resulting in an extremely short service life of the rubber mat.

For this purpose, it is possible to maintain the physical properties of chlorosulfonated polyethylene or chlorinated polyethylene, such as oil resistance, ozone resistance, weather resistance, and brightness, while also having excellent mechanical properties such as compression set and tensile strength. There is a strong demand for an elastomer composition containing an elastomeric gel and a method for producing the same.

(Problems to be Solved by the Invention) As a result of intensive research to solve the above problems, the present inventors have found that the mechanical properties of chlorosulfonated polyethylene or chlorinated polyethylene can be The present invention provides an elastomer composition containing a gel with excellent properties and a method for producing the same.

(Means for Solving the Problems) The present invention is characterized by an elastic body composition comprising chlorosulfonated polyethylene or chlorinated polyethylene, ethylene/α-olefin copolymer rubber, dehydrochloric acid scavenger, organic peroxide, and polypropylene. , and in advance kneading a dehydrochloric acid scavenger and an organic peroxide into chlorosulfonated polyethylene or chlorinated polyethylene, then kneading ethylene/α-olefin copolymer rubber, then melt-kneading polypropylene, and then dynamic heat treatment. A method of producing an elastic body composition is provided.

The present invention will be explained in detail below.

The chlorosulfonated polyethylene (hereinafter referred to as C6M) used in the elastomer composition of the present invention includes polyethylene, ethylene, butene-1 copolymer, ethylene-vinyl acetate copolymer, and ethylene-α-olefin copolymer. , ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer, etc., into which chlorine and chlorosulfonyl groups are introduced to make them rubber-like. The method for introducing chlorine and chlorosulfonyl groups is to dissolve the polymer in an inert organic solvent such as carbon tetrachloride, chlorine it by blowing chlorine gas, and then add chlorosulfonyl to react to introduce chlorosulfonyl groups. Alternatively, there is a method of introducing chlorine and a chlorosulfonyl group using chlorosulfonyl. The amount of chlorine is not particularly limited as long as C8M is rubbery, but 15 to 55% by weight of C3M is rubbery.

Additionally, chlorinated polyethylene (
Hereinafter referred to as CPE), powder or particles of the above polymer are suspended in water or dissolved in an inert organic solvent such as carbon tetrachloride, and chlorine gas is introduced into the mixture to form a rubber. It is something.

As long as CPE is rubbery like C8M, the amount of chlorine is not particularly limited, but 15 to 55% by weight of CPE is rubbery.

Although the manufacturing methods of CSM and CPH have been described above, the CSM or CPE used in the composition of the present invention is not limited to these manufacturing methods.

C5M or CPE in the rubber component used in the present invention
is used in a range of 60 to 97% by weight.

If the amount is less than 60% by weight, the physical properties of CSM or CPH such as oil resistance, ozone resistance, weather resistance, brightness, etc. will be impaired.

The ethylene/α-olefin copolymer rubber used in the present invention includes ethylene/propylene copolymer rubber (hereinafter referred to as EPT) having rubber elasticity, α-olefin copolymer rubber other than ethylene/propylene, ethylene/propylene/
α-olefin ternary copolymer rubber other than propylene, and non-conjugated diene monomers such as 1.3-butadiene, 1.4-
Pentadiene, 1,4-hexadiene, 6-methyl-1
, 5-hebutadiene, 5-methylene-2-norbornene,
5-alkynyl-2-norbornene, 2,5-turbonasien, 1,5-cyclooctadiene, 2-alkyl-
It is a rubber into which 2,5-turbonasien, dicyclopentadiene, etc. are introduced. Note that the above α-olefin contains 1-
Butene, l-pentene, 2-methyl-1-butene, 1-
Examples include hexeno, 3-methyl-1-pentene, and the like.

In the rubber component used in the present invention, 3 to 40% by weight of ethylene and a-olefin copolymer rubber is used. 3
If the amount is less than % by weight, the mechanical properties of the elastomer composition will not be improved.

The dehydrochlorination scavenger used in the elastomer composition of the present invention is:
It captures hydrochloric acid generated during dynamic heat treatment to partially crosslink CSM or CPE, and these include metal oxides, metal lead compounds, metal hydroxides, fatty acid metal soaps, such as magnesium oxide, Examples include calcium oxide, zinc oxide, -lead oxide, trilead tetroxide, tribasic lead sulfate, dibasic lead phosphite, calcium hydroxide, sodium stearate, magnesium stearate, calcium stearate, and the like. These may be used alone or in combination. The amount used is 0.1 to 30 parts by weight per 100 parts by weight of the rubber component of the present invention. If these dehydrochloric acid scavengers are not kneaded into CSM or CPE in advance, the mechanical properties of the resulting elastomer composition will be poor due to a decrease in dehydrochloric acid scavenging efficiency due to poor dispersion of the dehydrochloric acid scavengers, etc., which is not preferable.

The organic peroxide used in the present invention includes hydroperoxide, diacyl peroxide, ketone peroxide, peroxy ester, dialkyl peroxide, etc., such as t-butyl hydroperoxide, cumene hydroperoxide, etc. oxide, di-isopropylbenzene hydroperoxide, 2,5-
Dimethylhexane-2,5-cybidrobaroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, dicumyl peroxide, di-t
-butyl peroxide, n-butyl-4,4-bis(
Examples include t-butylperoxy)hexane, t-butylperoxybenzoate, benzoyl peroxide, and the like. These may be used alone or in combination. The amount of organic peroxide to be blended is 0.1 to 10 parts by weight per 100 parts by weight of the rubber component used in the present invention. 0
．． If the amount is less than 1 part by weight, mechanical properties such as compression set and tensile strength will be poor. If more than 10 parts by weight is used, the fluidity of the elastomer composition during molding at high temperatures will deteriorate, which is undesirable. The organic peroxide used in the present invention is an organic peroxide used for dynamic heat treatment of CSM or CPE after melt-kneading polypropylene (hereinafter referred to as PP). C5M or C before the end of
It is necessary to use an organic peroxide in which PE does not undergo partial crosslinking. As a guideline, it is preferable to use an organic peroxide whose decomposition temperature is 120° C. or higher to obtain a half-life of 1 minute. If these organic peroxides are not kneaded with C5M or CPE in advance, the resulting elastomer composition will have poor mechanical properties due to poor dispersion, etc., which is not preferable.

The equipment used for producing the elastomer composition of the present invention includes a mixer generally used for mixing rubber or resin, such as a roll kneader, a Banbury mixer, etc.
A double-arm kneader, a screw kneader, a rotor-type continuous kneader, etc. are used. Then, CSM or CPE in advance
Mixing of the dehydrochloric acid scavenger and organic peroxide refers to kneading using an incorrectly listed device. In this crosstalk, CSM or CP depends on the organic peroxide used.
When E is subjected to dynamic heat treatment and partially crosslinked, the resulting elastomer composition does not exhibit excellent mechanical properties.

For this purpose, it is important to knead CSM or CPE at a temperature that does not cause partial crosslinking with the organic peroxide.

A kneaded product obtained by previously kneading CSM or CPE with a dehydrochloric acid scavenger and an organic peroxide is then kneaded using a device in which EPT is incorrectly written. In this case of crosstalk, as mentioned above,
When CSM or CPE and ethylene/α-olefin copolymer rubber are dynamically heat-treated and partially crosslinked by the organic peroxide used, the resulting elastomer composition has poor mechanical properties.・
The α-olefin copolymer rubber must be kneaded at a temperature that does not cause partial crosslinking with the organic peroxide.

The PP used in the elastomer composition of the present invention is a homopolymer of propylene, or a combination of propylene and an α-olefin other than propylene, such as ethylene, pentene-1, butene-1,4-methyl pentene-1, etc. It is a polymer obtained by copolymerization and is crystalline. As a commercially available polypropylene, there is, for example, the polypropylene published in Naigai Kagaku Yakuhin Data A, Kobunshi NGC Co., Ltd. (1988). These may be used alone or in combination.

The amount used is 5 to 50 parts by weight of ribolybropyrene per 100 parts by weight of the rubber component used in the present invention.

If it is less than 5 parts by weight, the resulting elastomer composition will have poor fluidity during molding at high temperatures. If it exceeds 50 parts by weight, it will not exhibit elasticity, which is not preferable. The PP to be used is kneaded into a rubber mixture obtained by previously kneading CSM or CPE with a dehydrochloric acid scavenger and an organic peroxide, and then kneading ethylene/α-olefin copolymer rubber. This cross-mixing was carried out using an incorrectly listed device, and the kneading was carried out at a temperature above the melting point of the PP used. The crosstalk time is not particularly limited as long as the PP is melted and dispersed in the crosswire. What is important for this crosslinking is that C8M or CPE and ethylene/α-olefin copolymer rubber must not be subjected to dynamic heat treatment with an organic peroxide to cause partial crosslinking. If PP is partially crosslinked before it is melted and dispersed, the resulting elastomer composition will have significantly inferior mechanical properties. For this reason, it is necessary to pay particular attention to the selection of the organic peroxide used as described above. The main feature of the present invention is that after PP is melted and dispersed, C8M or CPE and ethylene/α-olefin copolymer rubber are partially crosslinked by dynamic heat treatment. The temperature of this dynamic heat treatment is preferably 140°C to 240°C. Dynamic heat treatment at a temperature below 140°C is not preferred because the resulting elastomer composition has poor mechanical properties. When subjected to dynamic heat treatment at temperatures exceeding 240°C, the resulting elastomer composition may have poor mechanical properties or
Otherwise, the color may change to blackish brown, so be careful.

The time required to perform the dynamic heat treatment varies depending on the type and amount of the dehydrochlorination scavenger, organic peroxide, etc. used, the type of crosstalk device, etc., and is not limited. The dynamic heat treatment referred to in the present invention refers to C8M or CPE and ethylene α
- Refers to the production of a gel by partially crosslinking olefin copolymer rubber at high temperatures while fluidizing it in a mixer. The amount of gel in the elastic body composition is not particularly restricted, but is preferably 20% by weight or more. If it is less than 20% by weight, the mechanical properties of the elastomer composition will be poor, which is not preferable. In addition, the amount of gel is determined based on JIS K 6 of the obtained elastic body composition.
From the unextracted benzene residue measured in a Harris cage made of 100 mesh stainless steel wire mesh according to 38 g,
Benzene is measured by excluding the amount of PP that is unextracted.

Although the elastomer composition of the present invention exhibits excellent mechanical properties by methods other than the production method of the present invention, the development thereof is particularly remarkable by the production method of the present invention.

The elastomer composition of the present invention may contain rubber compounding agents or resin compounding agents, such as plasticizers, softeners, radical inhibitors, anti-aging agents, ultraviolet absorbing agents, in the manufacturing process or in the obtained elastomer composition. A reinforcing agent such as carphone black, a white filler, a foaming agent, a lubricant, an antistatic agent, a coloring agent, etc. can be kneaded as necessary.

(Examples) Hereinafter, the present invention will be specifically explained with reference to Examples and Comparative Examples, but the present invention is not limited to these in any way.

The formulations used in Examples and Comparative Examples are shown in Table 1.

Examples 1 to 5 and Comparative Examples 1 to 3 In Example 1, 50% of magnesium oxide, DCP, and DOP were added to CSM in advance using the formulation 1 shown in Table 1.
The mixture was kneaded in a roll mixer at 0.degree. C., and then EPT was added and kneaded to the mixed material to obtain a rubber mixed material. Next, using a Brabender Plasticorder roller mixer type, put the PP and rubber mixture into a chamber with a set temperature of 140°C.
Using a roller mixer at 60 RPM, PP was melted and dispersed in the rubber kneaded material using heat generated from the rubber mixed wire material, and then dynamic heat treatment was performed. Next, Tsukurak N5-6 manufactured by Iriuchi Shinko Kagaku Kogyo Co., Ltd. was added and kneaded to obtain an elastic body composition. The temperature at which the obtained elastic body composition was taken out from the chamber was 195
It was ℃.

Next, the obtained elastomer composition was preheated for 4 minutes in a compression molding machine at 180°C, pressure molded for 2 minutes, and then cooled for 4 minutes in a compression cooler at 10°C to form a sheet with a thickness of 2 mm. Obtained. From the obtained sheet, the tensile strength was measured according to JIs K 6301 and No. 10 using No. 3 oil.
An immersion test was conducted at 0° C. for 70 hours to measure volume changes. In addition, the obtained elastic body composition was
℃ compression molding machine for 6 minutes and pressure molding for 3 minutes, then cooled in a 10℃ compression cooler for 6 minutes, and the thickness was 1.
A 2.7 mm sheet was obtained. From the obtained sheet, JI
Compression set test at 70°C according to S K 6301
, under test conditions of 22 hours.

In order to know the amount of gel consisting of CSM or CPE and EPT produced by dynamic heat treatment in a thermoplastic elastomer composition, according to JIS K 6388, 10
23 with a Harris basket made of stainless steel wire mesh with 0 mesh
Measurements were made of the unextracted residue in benzene at °C. The amount of gel composed of CSM or CPE and EPT produced was calculated using the following formula.

GL-LL -L2 However, GL Nigel amount (wt%) Ll: Unextracted residue in benzene of the elastic body composition (wt%) L2: PP amount (wt%) of the elastic body composition, measured tensile strength, compression set and gel amount are shown in Table-2.

Example-2 is an example other than using formulation-2 in Table-1.
I followed 1.

Example-3 is an example other than using formulation-3 in Table-1.
I followed 1.

Example-4 is an example other than using formulation-4 in Table-1.
I followed 1.

Example-5 uses formulation-2 in Table-1, in which magnesium oxide, DCP, and DOP are mixed in advance with C8M of Example-1 in a roll mixer at 50°C, and then EF is applied to the mixer.
The rubber kneaded product obtained by adding and kneading T is pre-EP-EPed into CSM.
The procedure of Example 1 was followed except that T, DCP and DOP were kneaded in a roll mixer at 50°C to obtain a rubber mixer.

Comparative Example-1 followed Example-1 except that Blend-5 was used.

Comparative Example-2 is an example other than the one using Formulation-6 in Table-1.
I followed 1.

Comparative Example 3 is a composition in which the rubber mixed wire material obtained by addition kneading of Example 1 is added and kneaded in Formulation 6 shown in Table 1, and then dynamic heat treatment is performed using a roll mixer at 180°C. Example 1 was followed except that a rubber mixed wire material was obtained and the dynamic heat treatment was not performed.

From Table 2, Example 1 obtained by the production method of the present invention
Compared to Comparative Example 1'-3, the elastomer compositions of ~5 are superior in mechanical properties such as compression set and tensile strength, and have small volume changes and oil resistance, which is the superior physical property of C8M or CPH. It turns out that it has a certain gender.

(Effects of the Invention) As is clear from the above description, the elastic body made of the chlorosulfonated polyethylene or chlorinated polyethylene of the present invention, ethylene/a-olefin copolymer rubber, dehydrochloric acid scavenger, organic peroxide, and polypropylene After kneading the composition and chlorosulfonated polyethylene or chlorinated polyethylene in advance with a dehydrochloric acid scavenger and an organic peroxide, then kneading ethylene/α-olefin copolymer rubber, and then melt-kneading polypropylene, According to the method for producing an elastomer composition, which is characterized by subjecting it to heat treatment, an elastomer composition containing a gel with excellent mechanical properties can be produced without impairing the excellent physical properties of chlorosulfonated polyethylene or chlorinated polyethylene. It turns out that the present invention is a body composition and a method for producing the same.

Claims (1)

[Scope of Claims] 1) 0.1 dehydrochloric acid scavenger per 100 parts by weight of a rubber component consisting of 60 to 97% by weight of chlorosulfonated polyethylene or chlorinated polyethylene and 3 to 40% by weight of ethylene/α-olefin copolymer rubber. ~30 parts by weight, 0 organic peroxides
．． An elastic composition comprising 1 to 10 parts by weight of polypropylene and 5 to 50 parts by weight of polypropylene. 2) Knead dehydrochloric acid scavenger and organic peroxide in chlorosulfonated polyethylene or chlorinated polyethylene in advance, then knead ethylene/α-olefin copolymer rubber, then melt-knead polypropylene, and then dynamic heat treatment. A method for producing an elastic body composition according to claim 1).